Groundhog Day is party time for 'marmotophiles,' scientists who have cozied up to the furry animals for years.

For most Americans, Groundhog Day is a quaint oddity or a movie starring Bill Murray. For Punxsutawney Phil Sowerby, the Pennsylvania critter who'll be dragged out of his burrow Saturday by men in top hats to look for his shadow, the day must be a supreme annoyance.

But for UCLA biologist Dan Blumstein, today's midwinter observance has become a reason to throw a party in honor of a creature that scientists have studied for decades.

Groundhogs are marmots — and through marmots, scientists hope to gain insight into the social behavior of animals, how they communicate and how their interactions influence the size of their population.

And so on Friday afternoon, Blumstein and a group of 30 or so fellow "marmotophiles" gathered in a spare hallway in the university's Life Sciences building and toasted groundhogs with cans of soda as a jazz mix played in the background.

"This is really the only holiday about animal behavior," Blumstein said.

Cat-sized, sharp-toothed groundhogs have a large range — from the Southeast up into the East Coast and Midwest, across Canada and even as far north as Alaska. Also known as woodchucks, they're the largest of the 14 or 15 marmot species (scientists are still debating the precise number).

Marmots are great animals for scientists to study, Blumstein said, because they're awake during the day and they "have an address," living in burrows that researchers can stake out over time. Blumstein, who has also studied the behavior of kangaroos, wallabies, hermit crabs, sea anemones, lizards, birds and people, has spent more than 13 years observing the colonies of yellow-bellied marmots who live at the Rocky Mountain Biological Laboratory in Crested Butte, Colo.

During summers in the field, he and colleagues have trapped marmots live using horse chow as bait, tagged them with "earrings," taken samples of their blood, and recorded the size of colonies as they waxed and waned. During winter, Blumstein has held a hibernating marmot in a lab, its body temperature just a couple of degrees above freezing. "It's like a hairy rock," he said.

A groundhog roused from hibernation that appears to be "looking for his shadow" is probably displaying a typical pattern, Blumstein said. Marmots rouse periodically during the winter to urinate, and near the end of the season they start to emerge from their burrows and scope out their territory for potential mates. Males typically wake before females.

Over the years, the scientists' observations have helped them understand how certain behaviors translate into success, or failure, for the colonies. Lately, they've focused on how the higher temperatures brought on by climate change might improve, or hinder, the marmots' reproductive success.

As recently as 2010, earlier springs seemed to be helping the marmots in Colorado by increasing the length of time they could eat. But then a longer-than-usual winter caused the population to crash.

Blumstein and his team are curious to see how the marmots will fare this spring after a winter that produced less early-season snow. That snow acts as a blanket for the animals; without it, their burrows may not have maintained the right temperature for healthy hibernation.

"We want to understand the limits of their flexibility," Blumstein said. "At some point, there may be too little snow to keep them warm over the winter."

One of Blumstein's students said she was studying gene expression in the Colorado marmots. Another student, from South America, was studying how marmots react to climate. They don't have marmots — or Groundhog Day — in South America, she noted.

Matthew Petelle, a graduate student, said he was interested in "marmot personality." Some are bold and others are shy, he said, and he's trying to figure out why the shy ones survive and thrive.

"We're the enthusiasts," he said of the partygoers at the science building, admitting that he'd probably be talking about marmots even in the absence of Groundhog Day.

Behind Petelle glowered Two-Buck Chuck, a groundhog Blumstein spied near a Kansas road more than 15 years ago.

"I was trying to study it and I was thinking it was alive," he said. "Then I realized, it's really not moving."

The animal had been hit by a car and had crawled off the road to die. Blumstein brought the body back to his lab and stuffed it, with help from his wife.

Other examples of groundhog kitsch were on display as well. There was a photograph of an obese yellow-bellied marmot eating Lay's potato chips in a Utah woman's kitchen and a page from the News of the World tabloid headlined "ATTACK OF THE 100 FT MARMOT."

"We made that into T-shirts," Blumstein said.

The jovial professor said he got the idea for the annual shindigs from his mentor, Kenneth Armitage, a University of Kansas behavioral ecologist who led the Rocky Mountain Biological Laboratory marmot project for 41 years.

Armitage, now retired, said he always promised his guests he'd serve groundhog at the parties.

As in "ground hog," or sausage.

"They'd kind of look at you funny, at first," he said of his grad students. "Then you'd see this big flash of relief."